How to Track changes to a supplier using the audit trail tables?

We would like to track all changes related to supplier by enabling audit trail. We have followed the instructions as per DOC ID 370874.1 (How to track the changes made to supplier name) however I have enabled the auditing on the ap_suppliers and ap_supplier_sites_all tables instead of the po_vendors and po_vendor_sites as stated in the document. The standard reporting that is available when enabling the auditing is not appropriate for our use so we are attempting to create custom reports. When creating these reports we are trying to use the shadow tables with suffixes of _a, _ac# and _av# and linking them back to the base tables in order to view the current data compared to the relevant values against the relevant supplier and supplier site that have been updated.